Mass-transfer correlations for dehumidification of air by triethylene glycol in a structured packed column

Structured packing represents the newest development in high-efficiency, high-capacity packing for heat and mass transfer in contrast to the traditional, randomly placed packing material. An experimental study for evaluating the heat- and mass-transfer coefficients in an air-desiccant contact system employing triethylene glycol and cross-corrugated cellulose structured packing (Celdek type) is carried out. The important design variables found to have the largest effect on the mass-transfer coefficient are as follows: the air and liquid flow rates, the air vapor pressure, and the solution vapor pressure. It is found that high liquid flow rates do not have a significant effect on the mass-transfer coefficient when the liquid to air flow rate ratio exceeds the value of 2. Two mass-transfer coefficient correlations are developed for normal and high liquid flow rates. These correlations predict the mass-transfer coefficient within 15%.